Study of Electron-Positron Annihilation into pi+pi- at 775 MeV with the Orsay Storage Ring

Augustin, J.E. ; Bizot, J.C. ; Buon, J. ; et al.
Phys.Rev.Lett. 20 (1968) 126-129, 1968.
Inspire Record 54563 DOI 10.17182/hepdata.21756

None

1 data table

No description provided.


Study of electron-positron annihilation into pi-plus pi-minus on the rho-neutral resonance

Augustin, J.E. ; Bizot, J.C. ; Buon, J. ; et al.
Phys.Lett.B 28 (1969) 508-512, 1969.
Inspire Record 56683 DOI 10.17182/hepdata.29076

The electromagnetic form factor of the pion has been determined in the ϱ o resonance region by measuring the absolute cross section of the reaction e + e − → π + π − with the Orsay storage ring. More than 800 pion pairs have been detected. The excitation curve has been fitted with a Breit-Wigner formula which leads to the following values: σ peak = (1.69 ± 0.21) 10 −30 cm 2 ; m ϱ = (770 ± 4) MeV ; Γ ϱ = (111 ± 6) MeV . The partial width of the ϱ o going into e + e − thus obtained is: Γ ϱ → e + e − =(7.36±0.7) keV .

1 data table

No description provided.


$\pi^+$ $\pi^-$ production in $e^+$ $e^-$ collisions and $\rho$-$\omega$ interference

Augustin, J.E. ; Benaksas, D. ; Buon, J. ; et al.
(1969) 35, 1969.
Inspire Record 58289 DOI 10.17182/hepdata.37427

None

1 data table

RELATIVE PRODUCTION OF PION PAIRS WITHOUT RADIATIVE CORRECTIONS.


pi+ pi- production by e+ e- annihilation in the rho energy range with the Orsay storage ring

Benaksas, D. ; Cosme, G. ; Jean-Marie, B. ; et al.
Phys.Lett.B 39 (1972) 289-293, 1972.
Inspire Record 73648 DOI 10.17182/hepdata.28321

A large solid angle detector has been used to observe two body events produced by electron-positron collisions in the Orsay storage ring. From the π + π − excitation curve in the ϱ region we have deduced the amplitude and the phase of the ω-ϱ interference, and the ϱ resonance paramaters: M ϱ = (775.4±7.3) MeV, Γ ϱ = (149.6 ± 23.2) MeV, √ B ( ω → π + π − ) = 0.19 ± 0.05, φ = (85.7 ± 15.3) 0 , σ ( e + e − → ϱ ) = (1.00 ± 0.13) μ b at S = M ϱ 2 , B ( ϱ → e + e − = (4.1 ± 0.5) × 10 −5 , Γ ( ϱ → e + e − ) = (6.1 ± 0.7) keV, ( g ϱ 2 /4 π ) = 2.26 ± 0.25, ( g ϱππ 2 /4 π ) = 2.84 ± 0.50.

1 data table

STATISTICAL ERRORS ONLY. CROSS SECTION AT RHO0 PEAK IS 1.00 +- 0.13 MUB FROM FIT.